The present invention is directed to the application of a fluid treatment or decoration agent to a continuously moving web. More particularly, it is directed to a device of the type having a drainage plate that spans the width of the web and which is inclined towards the web in a plane generally perpendicular to along or slightly curved with respect to the plane of the web. Such devices include a means for applying the fluid treatment or decoration agent onto the top of the drainage plate. The treatment or decoration agent moves down in a layer corresponding to the drop line above the top of the drainage plate, and gets onto the web from the bottom edge of the drainage plate.
Such devices are known in various variations, such as those which are evident from DE 27 43 742, DE 37 33 996, and DE 39 15 844, for example.
The fluid treatment or decoration agent, for example a dye fluid, moves on the surface of the drainage plate in a thin layer. This thin layer has a relatively large area, at which evaporation takes place, with correspondingly strong cooling of the small amount of fluid mass. Such cooling of the treatment or decoration agent is not desirable, in many cases. In most cases, the treatment or decoration agent has just been brought to an elevated temperature which is the optimum temperature for the treatment effect. As the fluid passes over the drainage plate, this temperature drops in a manner which is difficult to foresee or control.